The purpose of this research is to better understand the relationships of genetic control, molecular structure, and function of hemoglobins in humans and other animals. The work includes structural characterization of abnormal human hemoglogins, the zeta chain of embryonic hemoglobin Portland 1, and selected animal hemoglobins. Comparisons of the sequences determined will be made with those already known for normals and other animals. Parallel studies are being made of the functional properties of the new abnormal hemoglobins which are discovered. Special emphasis is placed on comparisons of functional properties of mutant hemoglobins with different substitutions at the same residue position.